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TO ALL WHOM IT MAY CONCERN: l

Be it known that I, CHARLES H. BROOKBANK, of Connersville, in the countyof Fayette, and State of Indiuna, have invented a new and improvedHeadfBlock for Saw-Mills and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art .to make and use the same, reference being had to theaccompanying drawings, forming part of this specification, in which-Figure 1 represents a rear. elevation of my invention. v

Figure 2 is a plan or top view of the same.

l Figure 3 is a. detail sectional view of the same on an enlargedlscale, the plane of section being indicated by the line x x, fig. 2. I

Figure 4 is a detail sectionalwiew of 'the same, the plane of sectionbeing indicated by the line y y, iig. 2.

Similar letters of reference indicate like parts. 4

This invention relates toa device by which head-blocks can be moved on asaw-carriage of suitable construction, so that a log can be` setVthereby to the saw after a board has been sawed off; which device canbe regulated to feed the log any -required distance for cuttingboards ofany desired thickness.

The invention consists in the construction and arrangement of the partsby which the screw-shafts, on which the head-blocks slide, are operated,so that they are only revolved in one direction while the log is to hefed, being handled by a vertical lever, the lower end of which ispivoted to the carriage, while its upper portion is connected with ahorizontal sliding-bar. A rack secured to the latter ts into the teethof a pinion, which is hung so as to turn loose on the aforesaidscrew-shaft, and which is connected with the same by a pawl andratchet-wheel, whereby, asthe pinion is revolved by the motion of thesliding bar, ythe screw-shaft is carried'v around in one direction, andthe head-block is moved forward, while, when the pinion is revolved inthe opposite direction during and by the return move of the aforesaidsliding bar, it will turn loose onthe shaft. When the blocks are to beset back for a. new log, the screw-shafts have to be turned by hand. Thelength of stroke allowed for the lever and sliding bar regulates thedistance for each move of the blocks, and consequently the thickness ofboard sawed. Y

A represents a saw-carriage for a circular saw. It is made of anysuitable material and form, and is operated by any suitable device. B Bare two or more beams, which are arranged on top of the carriage,extending across the same, their upper surfaces acting as rests for thelog. These beams are made hollow, and are firmly secured to the carriageby means of screws, or other suitable devices. Within each beam isarranged a horizontal shaft, C, which extends from end to end of eachbeam, and has its bcaringslin the ends of the beam. Between the ends ofthe beam each shaft C is provided with a single or double screwthread,as shown. D D are the head-blocks, which slide upon the beams, and haveeach a downward extension which passes through a slot in.

the upper face of the hollow beam, and which encloses the screw C,acting as a nut on the same. Thus, as the screw C is turned in eitherone or the other direction, the block which is connected with it iseither moved forward or backward, as may be desired. To the rear end ofeach beam is secured an arm, la, which forms the support for ahorizontal sliding rod, E, which is arranged in rear of the carriage,parallel with the track ofthe carriage, and at right angles with-thebeams. To this rod are secured adjustable slides n n, which are toothedon their under sides, as shown, and which mesh into pinions b, of whichone is hung loose on the rear end of each shaft C. On the outside ofeach pinion b is formed a ratchet-wheel, c, (see figs 3 and 4,) whichmoves with the pinion. d is a. wheel,'which is mounted on the extremerear end ofthe shaft C, and revolves with the same. A pawl, e, ispivoted to its inner side, and is forced upon the ratchet-wheel c by aspring,f.

As the bar E is moved in the direction of the arrow 1, in iig. I, itsteeth mesh into the pinion, and the latter will be turned in thedirection of the arrow 2. The teeth on the ratchet will then catchagainst the end of the pawl, and the pinion will thus carry the wheel daround with it, and consequently the shaft G, 'as the wheel d is firmlykeyed on the shaft. The screw on the shaft will operate the headblocks,and will move the same forward. When the bar E is moved in the oppositedirection, the pawl will slip on the ratchet-wheel, and the shaft C willnot lie-turned. The rod E is secured to a bar, G, which is pivoted to a.lever, F, the latter being pivoted to the' carriage, as shown in g. 1.By means of this lever the rod E is moved in the direction of the arrowlwhen ever a board has been sawcd ci?, and the log will then be set tothe saw again. The bar gvisisecured to a sliding sleeve, IL, on the barE, said sleeve being held in position by a set-screw, z', as shown. Thestroke of the lever F is regulated by means of two pins 7c 1c, which arearranged. in the carriage. By increasing the distance between these pinsthe lever is allowed to make a longer stroke, and the head-blocks arethereby moved a. greater distance during each stroke. By means of theset-screw z' and sleeve 71. the length of stroke of the bar E can heincreased or diminished without increasing or diminishing the stroke ofthe lever F. When a log has been cut up, and the head-blocks are to bedrawn back, each screw-shaft C must be turned for the purpose. Thewheels d re therefore each provided with a handle, Z, by which the shaftcan be turned. This handle is a continuation of the pin by which thepnwl is pivoted to the wheel d, and thus by turning the handle the pawlcan he thrown out of the ratchet-wheel and the sha-ft C returned, sothat the head-blocks are drawn back from the saw. m m are the dogs,which are pivoted to the head-blocks, and by which the log is secured tothe blocks. l I am aware that Letters Patent were granted to J. H.Clemens, bearing date April 9, 1867, for improvements in head-blocks forsaw-mills, but the subject-matter of this I do not claim` as it forms nopart of my invention; but

What I claim as new, and desire to secure by Letters Patent, is 1. Therod E, provided with the adjustable toothed slides n, and operated bymeans of the lever F pivoted to the carriage, and connected to said rodby means ofthe sliding sleeve h and bar g, all arranged as described forthe purpose specified.

2. The pins 7c 7c and sliding sleeve h, regulating the stroke of thelever F, whereby the movement of the head-block is determined, as hereinshown and described.

3. The pinion b, having formed upon its inner side the ratchet-wheel c,turning loosely upon the screwshaft C, and connected to the wheel d bythe pawl e and springf, as .herein described, and operated to move thehead-block forward by the ratchet-bar E, and to withdraiv saidhead-block by means of the crank l independent of the ratchet-rod, allarranged as described for the purpose specified.`

4. The arrangement of the pivoted lever F, connected by the bar g andslide h to the ratchet-rod E, the screwrod C, pinion b, ratchet e,crank-wheel d, pawl g, springf, and head-block D, as herein set forthfor the purpose specified.

5. Feeding the log to the saw the required distance at one stroke of thelever F, through the medium ofl the retehet-bar E, pinion 11, ratchet c,wheel d, and screw-rod C, as herein shown and described.

CHARLES H. BROOKBANK., Witnesses:

Josnrn G. Gnorr, SAM. H. BECK, JAKE KLUM.

